1. Field of the Invention
The present invention relates to a method of manufacturing dimethyl ether (DME).
2. Description of the Related Art
Liquefied petroleum gas (LPG), which is used as, for example, a fuel, is very costly. Specifically, the price of LPG, if delivered to the consuming district, e.g., household, is more than 10 times as high as the import price. Therefore, dimethyl ether attracts attention as a substitute for LPG in recent years, thus utilization studies are now being carried out.
It is customary to manufacture dimethyl ether in the producing district of a natural gas by using as the raw material a natural gas or methanol synthesized from the natural gas. The manufactured dimethyl ether is liquefied under a high pressure and the liquefied dimethyl ether is loaded in a high pressure tank or cylinder for transport to the consuming district. Alternatively, the manufactured dimethyl ether is cooled to temperatures lower than −25° C. and packed in a freezing tank under atmospheric pressure for transport to the consuming district.
However, dimethyl ether gives rise to the problems transportation and storage costs. Also, where dimethyl ether is stored in a high pressure tank, it is necessary to supervise the safety of the high pressure gas in the dimethyl ether producing district.